This is FANTASITC! And the amount of polish in such a short time is commendable: Mini-maps, character customization, enemy variation, boss fights, and more. I loved the bouncing bullet mechanic for ricochet shots around corners in later levels. Not sure it was an intended feature, but I did use the pistol ricochet to move myself around faster in those later levels (post boss where they were more abundant).
I think it has already been said, but a suggested feature: Throwing the empty weapon as a blunt object to do damage (with it disappearing on hit like the other projectiles)
And last but not least: Shoutout for the Barrel Goblin representation!